Blog · Ohio & Michigan
Ice dams in Ohio and Michigan: why they form and how to stop them
Ice dams start in the attic, not on the shingles. How they form, the damage they cause, what to do during one, and the fixes that stop them for good.
By Jonathan Blake · · 2 min read
- Ice dams form when attic heat melts roof snow that refreezes at the cold eaves.
- Air sealing, insulation and ventilation fix the cause. Heat cables and roof rakes only manage symptoms.
- Ice barrier under the shingles at the eaves limits damage when dams do form.
Every winter across Ohio and Michigan, thick ridges of ice build up along roof edges and icicles hang from the gutters. Behind that ice, meltwater backs up under the shingles and shows up as stains on ceilings and walls. Here’s why it happens and how to stop it.
How an ice dam forms
- Heat from the house leaks into the attic through gaps around light fixtures, attic hatches, plumbing and chimneys, and through thin insulation.
- That heat warms the roof deck, and the snow on the upper roof melts even when it’s below freezing outside.
- Meltwater runs down to the eaves, which hang out past the warm walls and stay cold.
- The water refreezes into a ridge of ice. More meltwater pools behind it and works up under the shingles.
Shingles are designed to shed water running downhill, not to hold back a pond. That is why ice dams leak even on newer roofs.
Signs you have an ice dam problem
- Thick ice along the eaves and large icicles, especially over heated rooms.
- Water stains on ceilings near exterior walls, or peeling paint below windows.
- Frost or dripping on the underside of the roof deck when you look in the attic.
- Snow melting off the upper roof while neighbors’ roofs stay covered.
What to do during an ice dam
- Protect the inside. Catch drips, move belongings and check for wet insulation in the attic.
- Stay off the roof. Use a roof rake from the ground to pull snow off the lower few feet of roof, if you can do it safely.
- Call a professional for leaks. Steaming channels through the ice is safer for you and the shingles than chipping.
- Document it. Photos and dates help with insurance and repairs.
The permanent fix: keep heat out of the attic
- Air seal the attic floor: top plates, light fixtures, attic hatch, plumbing and duct penetrations. This usually matters most.
- Add insulation where it’s thin, so less heat reaches the attic.
- Ventilate with clear soffit intakes and ridge or roof vents, so cold outside air keeps the deck cold.
- Vent fans outside. Bath and kitchen fans that dump warm, moist air into the attic make ice dams and frost worse.
What a roofer adds
In areas with a history of ice dams, the model residential code requires an ice barrier underlayment from the eave to at least 24 inches inside the exterior wall line. When you replace a roof, ask how far up the ice barrier will go, whether valleys get it too, and how ventilation will be handled. Our roof replacement planner lists these items so every quote covers them, and our roof repair triage walks through what to do when water is coming in now.
Run your numbers
Quick roof estimate
Provisional planning range (our setting, not a quote or market average). Real prices depend on condition, access and scope.
What this estimate does and doesn't cover
- It all depends on the roof. Condition, material, pitch, number of layers, access and local code can move the price well outside this range. Treat it as a first budget number, not a price.
- Roof area is a rough guess. We turn living area into roof area using your stories, a 10% allowance for overhangs and your pitch. Garages, porches, dormers, valleys and complex shapes are not counted. A measurement report or an on-site measurement will differ.
- The dollar band is our own provisional setting, informed by published guides. It is not a verified Ohio or Michigan market average, not a contractor quote and not an offer.
- Assumes a straightforward replacement: one layer torn off, standard underlayment, ice barrier at eaves, flashing and cleanup.
- Not included: rotted decking, extra layers, framing or structural repair, major ventilation changes, chimney work, skylights, gutters, permits, steep or difficult access, and insurance-related work.
- Repairs are not priced. Leaks, storm damage and small repairs need an inspection.
- Stay off the roof. Measure from the ground or plans, and get a written proposal from a licensed, insured contractor before you decide.
See how we set ranges and our disclosures.
Questions readers ask
Are ice dams covered by homeowners insurance?
Many policies cover sudden water damage inside the home from an ice dam, but not the cost of fixing the underlying cause. Coverage depends on your policy. Ask your agent.
Should I chip ice off my roof?
No. Chipping and climbing on an icy roof is dangerous and damages shingles. If water is coming in, a professional can steam channels through the dam safely.
Do heated cables stop ice dams?
They can keep a channel open for meltwater in trouble spots, but they use electricity and do not fix the heat loss causing the problem. Think of them as a stopgap.
Will a new roof stop ice dams?
A new roof with ice barrier at the eaves limits leaks, but ice dams will still form if the attic is losing heat. Fix air sealing, insulation and ventilation at the same time.
Do gutters cause ice dams?
No, but gutters fill with ice during a dam, which adds weight. Keeping them clean in fall helps meltwater drain on milder days.
Sources
- 2021 International Residential Code, Section R905.1.2 (ice barrier), International Code Council